Weaning and concentrate supplementation on the characteristics of carcass cuts and longissimus muscle of Suffolk lambs finished on pasture

Sergio Rodrigo Fernandes,Cláudio José Araújo Da Silva,Alda Lúcia Gomes Monteiro,Marina Gabriela Berchiol Da Silva,Júlia Marina Zanotelli,Pedro Henrique Nicolau Pinto,Paulo Rossi Junior

doi:10.4025/actascianimsci.v44i1.53445

Abstract

The aim of this study was to evaluate the influence of weaning and concentrate supplementation on the characteristics of carcass cuts and longissimus muscle of Suffolk lambs finished on a Tifton 85 (Cynodon spp.) pasture. Weaning and concentrate supplementation strategies were evaluated in four finishing systems: i) non-weaned and non-supplemented lambs; ii) non-weaned lambs supplemented with concentrate in creep feeding; iii) weaned and non-supplemented lambs; and iv) weaned lambs supplemented with concentrate. In the systems with weaning, lambs were weaned at 46 ± 6 days of age. In the systems with supplementation, the concentrate was offered daily at 2% of lambs’ body weight. Weaning led to a decrease, whereas supplementation led to an increase in carcass cut weights. Supplemented lambs had lower yields of neck and uncovered ribs, and higher yields of breast + flank and loin. The characteristics of loin eye and fat thickness over the longissimus muscle presented lower values in weaned lambs and higher values in supplemented lambs. Keeping lambs with their dams and offering concentrate supplementation until slaughter are strategies recommended to obtain heavier cuts with increased muscularity and fat content.

Highlights

In lamb production systems, weaning is used to improve productivity and accelerate the recovery of ewes’ body condition score (Fernandes et al, 2011)
Studies performed in the Brazilian subtropical region showed that Suffolk lambs finished at 32–37 kg of body weight (BW) on Tifton 85 pasture presented an average daily gain of 135 – 280 g day-1 in systems without weaning; 50 – 110 g day-1 in systems with weaning and without supplementation; and around 150 g day-1 when they received concentrate supplementation post-weaning (Silva et al, 2014; Poli et al, 2020)
To evaluate the weaning and concentrate supplementation strategies, four finishing systems were established on a Tifton 85 pasture: i) non-weaned and non-supplemented lambs; ii) non-weaned lambs supplemented with concentrate in creep feeding; iii) weaned and non-supplemented lambs; and iv) weaned lambs supplemented with concentrate

Summary

Introduction

In lamb production systems, weaning is used to improve productivity and accelerate the recovery of ewes’ body condition score (Fernandes et al, 2011). This strategy allows an early return of ewes to cyclicity, reducing the interval between parturitions, and increasing the rate of lambs produced per ewe year (Oliveira et al, 2014). Supplementation in grazing systems is a strategy to mitigate the variations in forage allowance and forage quality of pasture, improving sheep performance, and increasing the number of animals to slaughter (Geron et al, 2012; Alves et al, 2013; Silva et al, 2019). The protein– energy supplementation offered in creep feeding has been widely used to improve lambs’ growth, resulting in

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